共 40 条
Coating Fe3O4 magnetic nanoparticles with humic acid for high efficient removal of heavy metals in water
被引:914
作者:
Liu, Jing-Fu
[1
]
Zhao, Zong-Shan
[1
]
Jiang, Gui-Bin
[1
]
机构:
[1] Chinese Acad Sci, Res Ctr Ecoenvironm Sci, State Key Lab Environm Chem & Ecotoxicol, Beijing 100085, Peoples R China
基金:
中国国家自然科学基金;
关键词:
D O I:
10.1021/es800924c
中图分类号:
X [环境科学、安全科学];
学科分类号:
08 ;
0830 ;
摘要:
Humic acid (HA) coated Fe3O4 nanciparticles (Fe3O4/HA) were developed for the removal of toxic Hg(II), Pb(II), Cd(II), and Cu(II) from water. Fe3O4/HA were prepared by a coprecipitation procedure with cheap and environmentally friendly iron salts and HA. TOC and XPS analysis showed the as-prepared Fe3O4/ HA contains similar to 11% (w/w) of HA which are fractions abundant in O and N-based functional groups. TEM images and laser particle size analysis revealed the Fe3O4/HA (with similar to 10 nm Fe3O4 cores) aggregated in aqueous suspensions to form aggregates with an average hydrodynamic size of similar to 140 nm. With a saturation magnetization of 79.6 emu/g, the Fe3O4/HA can be simply recovered from water with magnetic separations at low magnetic field gradients within a few minutes. Sorption of the heavy metals to Fe3O4/HA reached equilibrium in less than 15 min, and agreed well to the Langmuir adsorption model with maximum adsorption capacities from 46.3 to 97.7 mg/g. The Fe3O4/HA was stable in tap water, natural waters, and acidic/ basic solutions ranging from 0.1 M HCl to 2 M NaOH with low leaching of Fe (<= 3.7%) and HA (<= 5.3%). The Fe3O4/HA was able to remove over 99% of Hg(II) and Pb(II) and over 95% of COO and Cd(II) in natural and tap water at optimized pH. Leaching back of the Fe3O4/HA sorbed heavy metals in water was found to be negligible.
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页码:6949 / 6954
页数:6
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